Commit Graph

409 Commits

Author SHA1 Message Date
Eitan Adler
36daf0495a - change "is is" to "is" or "it is"
- change "the the" to "the"

Approved by:	lstewart
Approved by:	sahil (mentor)
MFC after:	3 days
2011-10-16 14:30:28 +00:00
Konstantin Belousov
ef9cbd91d0 Handle the R_386_TLS_TPOFF32 relocation, which is similar to R_386_TLS_TPOFF,
but with negative relocation value.

Found by:	mpfr test suite, pointed to by ale
Reviewed by:	kan
MFC after:	1 week
2011-10-08 12:42:19 +00:00
Konstantin Belousov
4e63ea7386 Setting up TLS block for the main thread must be done after the
relocations are processed, since tls initialization section might be
itself subject for relocations. Only set up of the block is postponed,
the tls block offsets are allocated before relocation processing, since
TLS-related relocations may need offsets ready.

Reported by:	ale
PR:	threads/161344
Reviewed by:	kan
MFC after:	1 week
2011-10-08 12:39:47 +00:00
Konstantin Belousov
750b5e3134 Restore the writing of the .bss sections of the dsos (not the main
executable) after r190885. The whole region for the dso is mmaped with
MAP_NOCORE flag, doing only mprotect(2) over .bss prevented it from
writing .bss to core files.

Revert the optimization of using mprotect(2) to establish .bss, overlap
the section with mmap(2).

Reported by:	attilio
Reviewed by:	attilio, emaste
Approved by:	re (bz)
MFC after:	2 weeks
2011-09-20 21:49:54 +00:00
Konstantin Belousov
f785588713 Use the proper dynamic tls block to calculate the tls variable address
in case tls data generation was updated.

PR:	misc/160721
Submitted by:	"Thinker K.F. Li" <thinker codemud net>
Tested by:	flo
Approved by:	re (bz)
MFC after:	1 week
2011-09-15 11:50:09 +00:00
Konstantin Belousov
b236731716 Do not use the function pointers for the internal operation of rtld_printf()
functions. The _rtld_error() function might be called early during the rtld
bootstrap, in which case function pointers are not yet functional on ia64
due to required relocations not yet performed.

Reported, reviewed and tested by:	marcel
Approved by:	re (bz)
2011-09-06 10:21:33 +00:00
Dimitry Andric
cce0f33cda When libexec/rtld-elf/rtld.c is compiled with clang, the r_debug_state()
function (a hook necessary for gdb support), is inlined, but since the
function contains no code, no calls to it are generated.  When gdb is
debugging a dynamically linked program, this causes backtraces to be
corrupted.

Fix it by marking the function __noinline, and inserting an empty asm
statement, that pretends to clobber memory.  This forces the compiler to
emit calls to r_debug_state() throughout rtld.c.

Approved by:	re (kib)
2011-09-03 11:41:00 +00:00
Konstantin Belousov
0e9a260520 Rtld links with the specially built pic static libc library to get some
C runtime services, like printf(). Unfortunately, the multithread-safeness
measures in the libc do not work in rtld environment.

Rip the kernel printf() implementation and use it in the rtld instead of
libc version. This printf does not require any shared global data and thus
is mt-safe. Systematically use rtld_printf() and related functions, remove
the calls to err(3).

Note that stdio is still pulled from libc due to libmap implementaion using
fopen(). This is safe but unoptimal, and can be changed later.

Reported and tested by:	pgj
Diagnosed and reviewed by:	kan (previous version)
Approved by:	re (bz)
2011-08-24 20:05:13 +00:00
Ben Laurie
5f301949ef Fix clang warnings.
Approved by:	philip (mentor)
2011-06-18 13:56:33 +00:00
Nathan Whitehorn
f33b8de1dc Compile RTLD with global dot symbols on 64-bit PowerPC, as a crutch for
GDB's ability to locate r_debug_state (which is actually the only function
that need be compiled this way).
2011-06-08 13:23:35 +00:00
Andriy Gapon
6014c8de1d rtld: eliminate double call to close(2) that may occur in load_object
The second close(2) call resulted in heisenbugs in some multi-threaded
applications where e.g. dlopen(3) call in one thread could close a file
descriptor for a file having been opened in other thread concurrently.

My litmus test for this issue was an openoffice.org build.

Reviewed by:	jhb
MFC after:	2 weeks
2011-03-25 18:23:10 +00:00
Marius Strobl
080ca1a51b - Add support for TLS relocations.
- Emitt an error when encountering an unsupported and in case of the
  kernel also for unaligned relocations.
- Fix R_SPARC_LOX10 relocations. Apparently these are hardly ever used.
2011-03-11 21:08:02 +00:00
Marius Strobl
cb32ba5229 - Remove clause 3 and 4 from TNF licenses. [1]
- Add the _RF_X committed in r212998 also to the tables in the sparc64
  reloc.c in order reduce differences between the kernel and the userland
  source. This results in no functional change though.
- Fix further inconsistencies in the abbreviations of the names of the
  relocations.
- Further whitespace fixes.

Obtained from:	NetBSD [1]
2011-03-11 20:30:58 +00:00
Nathan Whitehorn
a43ce960b5 Remove dead code that snuck in from the 32-bit PowerPC version of this
file. The error being checked for does not exist on 64-bit systems.
2011-03-07 20:32:46 +00:00
Marius Strobl
25b31a9496 - With the addition of TLS support binutils started to make the addend
values for resolved symbols relative to relocbase instead of sections
  so detect this case and handle as appropriate, which allows using
  kernel modules linked with affected versions of binutils. Actually I
  think this is a bug in binutils but given that apparently nobody
  complained for nearly six years and powerpc has basically the same
  workaround I decided to put it in for the sparc64 kernel, too.
- Fix R_SPARC_HIX22 relocations. Apparently these are hardly ever used.
2011-03-06 15:20:11 +00:00
Marius Strobl
d374d11285 - Consistently abbreviate the names of the relocations.
- End sentences with dots.
- Fix whitespace.
2011-03-06 13:25:46 +00:00
Nathan Whitehorn
7a159e4971 Remove a hack made obsolete by the binutils 2.17 merge. 2011-02-20 16:16:42 +00:00
Nathan Whitehorn
79c77d726e Turn off default generation of userland dot symbols on powerpc64 now that
we have a binutils that supports it. Kernel dot symbols remain on to assist
DDB.
2011-02-18 21:44:53 +00:00
Konstantin Belousov
a7bc470a84 Use sigsetjmp/siglongjmp with disabled signal mask access for
lock upgrade in rtld. There is no need to care about the mask,
which causes a lot of unneeded sigprocmask(2) calls during each
symbol lookup.
2011-02-09 09:20:27 +00:00
Konstantin Belousov
54a6cb4e7b Fix grammar in comment.
Pointy hat to:	kib
MFC after:	1 week
2011-01-30 16:21:25 +00:00
Konstantin Belousov
2c95328822 Make ldd(1) work when versioned dependency file is cannot be loaded.
Instead of aborting in locate_dependency(), propagate the error to
caller. The rtld startup function does the right thing with an error
from rtld_verify_versions(), depending on the mode of operation.

Reported by:	maho
In collaboration with:	kan
MFC after:	1 week
2011-01-30 16:14:09 +00:00
Alexander Kabaev
20a86d1f34 Eliminate the use of symlook_needed function in favor of DAGS.
Place elements on DAG lists in breadth-first order. This allows us to
walk pre-built list in all cases where breadth-first dependency chain
enumeration is required.

Fix dlsym on special handle obtained by dlopen(NULL, ...) to do what
comment claims it does. Take advantage of recently added symlook_global
function to iterate over main objects and global DAGs lists properly in
search of a symbol. Since rtld itself provides part of the global
namespace, search rtld_obj too.

Remove recursion from init_dag and symlook_needed functions. Use
symlook_needed for ELF filtee processing only and change lookup order
used in the function to match the order used by Solaris runtime linker
under same circumstances. While there, fix weak symbol handling in the
loop so that we return the first weak symbol definition if no strong one
was found, instead of the last one.

Reviewed by: kib
MFC after:   1 month
2011-01-28 23:44:57 +00:00
Sergey Kandaurov
3fce3875e5 Remove SuperH architecture from a comment as we do not support it.
Presumably it was leaked from NetBSD together with rtld-elf mips support.

Approved by:	kib (mentor)
MFC after:	3 days
2011-01-28 17:30:24 +00:00
Konstantin Belousov
cb38d4941c When loading dso without PT_GNU_STACK phdr, only call
__pthread_map_stacks_exec() on architectures that allow executable
stacks.

Reported and tested by:	marcel (ia64)
2011-01-25 21:12:31 +00:00
Konstantin Belousov
4503c8f7bd Fix get_program_var_addr() when type of the resolved symbol is functional.
Use make_function_pointer then, otherwise ia64 is broken.

Reported and tested by:	marcel
2011-01-25 21:04:55 +00:00
Konstantin Belousov
cb48d32015 Add my copyright.
Discussed with:	kan
2011-01-22 19:25:49 +00:00
Konstantin Belousov
8ae32158df Mark rtld on PowerPC as not requiring executable stack.
Reviewed and tested by:	nwhitehorn
2011-01-14 11:32:31 +00:00
Konstantin Belousov
bf390c1fbd get_program_var_addr() must prefer the strong symbol to the weak
one. Search global objects, together with main object and
dependencies, for the requested symbol.

Move the common code from symlook_default() into new helper
symlook_global(), and use it both in symlook_global() and
get_program_var_addr().

Supply lock state to get_program_var_addr().

Reviewed by:	kan
Tested by:	Mykola Dzham <i levsha me>
2011-01-10 16:09:35 +00:00
Konstantin Belousov
212f264cd6 In rtld, read the initial stack access mode from AT_STACKPROT as set
by kernel, and parse PT_GNU_STACK phdr from linked and loaded dsos.

If the loaded dso requires executable stack, as specified by PF_X bit
of p_flags of PT_GNU_STACK phdr, but current stack protection does not
permit execution, the __pthread_map_stacks_exec symbol is looked up
and called. It should be implemented in libc or threading library and
change the protection mode of all thread stacks to be executable.

Provide a private interface _rtld_get_stack_prot() to export the stack
access mode as calculated by rtld.

Reviewed by:	   kan
2011-01-08 17:11:49 +00:00
Konstantin Belousov
3ad6376e56 Add section .note.GNU-stack for assembly files used by 386 and amd64. 2011-01-07 16:07:05 +00:00
Dimitry Andric
9a17b89ccf Sort -mno-(mmx|3dnow|sse|sse2|sse3) options consistently throughout the
tree.

Submitted by:	arundel
2011-01-05 21:23:26 +00:00
Dimitry Andric
e172464728 On amd64 and i386, tell the compiler to refrain from generating SSE,
3DNow, MMX and floating point instructions in rtld-elf.

Otherwise, _rtld_bind() (and whatever it calls) could possibly clobber
function arguments that are passed in SSE/3DNow/MMX/FP registers,
usually floating point values.  This can happen, for example, when clang
generates SSE code for memset() or memcpy() calls.

One symptom of this is sshd dying early on amd64 with "PRNG not seeded",
which is ultimately caused by libcrypto.so.6 calling RAND_add() with a
double parameter.  That parameter is passed via %xmm0, which gets wiped
out by an SSE memset() in _rtld_bind().

Reviewed by:	kib, kan
2011-01-04 20:51:28 +00:00
Dimitry Andric
7606ddab28 Remove '-elf' from build flags for libexec/rtld-elf for amd64 and i386.
ELF has been the default format for almost 12 years now.
2011-01-04 20:26:41 +00:00
Nathan Whitehorn
9cc92083b0 Add support for R_PPC64_UADDR64 relocations. 2011-01-03 23:11:52 +00:00
Nathan Whitehorn
071a51cf97 Fix an error in the ABI in rtld_bind_start(). When passing arguments to a
C function, the caller's stack frame must have room to store all of the
arguments to that function. While here, fix stack frame alignment issues.

Without this change, the compiler will save r3 and r4 into the caller's
stack frame before calling setjmp() in _rtld_bind(). These would then
overwrite arguments to the newly-bound function, causing eventual failures.
2010-12-28 22:31:59 +00:00
Alexander Kabaev
43c9be3d24 Fix an apparent cop-and-paste mistake in previous commit.
This makes dlsym(RTLD_DEFAULT) work properly again.
2010-12-27 00:30:29 +00:00
Konstantin Belousov
8569deaf1c Implement support for ELF filters in rtld. Both normal and auxillary
filters are implemented.

Filtees are loaded on demand, unless LD_LOADFLTR environment variable
is set or -z loadfltr was specified during the linking. This forces
rtld to upgrade read-locked rtld_bind_lock to write lock when it
encounters an object with filter during symbol lookup.

Consolidate common arguments of the symbol lookup functions in the
SymLook structure.  Track the state of the rtld locks in the
RtldLockState structure. Pass local RtldLockState through the rtld
symbol lookup calls to allow lock upgrades.

Reviewed by:	kan
Tested by:	Mykola Dzham <i levsha me>, nwhitehorn (powerpc)
2010-12-25 08:51:20 +00:00
Konstantin Belousov
06786ccfb3 Add a hook to pass debug flags to the build of rtld when doing make in
the rtld directory.

Reviewed by:	kan
2010-12-25 08:42:38 +00:00
Jaakko Heinonen
4ef75f147a If dlclose() is called recursively from a _fini() function, the inner
dlclose() call may unload the object of the outer call prematurely
because objects are unreferenced before _fini() calls.

Fix this by unreferencing objects after calling objlist_call_fini() in
dlclose(). Therefore objlist_call_fini() now calls the fini function if
the reference count of an object is 1. In addition we must restart the
list_fini traversal after every _fini() call because another dlclose()
call might have modified the reference counts.

Add an XXX comment to objlist_call_fini() about possible race with
dlopen().

PR:		133246, 149464
Reviewed by:	kan, kib
2010-12-16 16:56:44 +00:00
Dimitry Andric
b9c727d84e Use -fPIC to build libexec/rtld-elf on sparc64, so it will also be able
to link with newer binutils, without overflowing the GOT.

Obtained from:	projects/binutils-2.17
2010-11-11 22:53:55 +00:00
Konstantin Belousov
4495a80b97 In r214728, if dlopen() is called for the object that has been already
loaded as a dependency and marked -z nodlopen, object' DAG is already
initialized by load_needed_objects(). Due to this, the init_dag() call
from dlopen() does not increment refcount for the object [1].

Change init_dag() to not increment DAG refcount. Require explicit calls
to ref_dag() to increment, and assert that ref_dag() and unref_dag()
are called for root that has dag initialized. To fix the noted issue,
unconditionally call both init_dag() and ref_dag() in dlopen() for the
case when the object was already loaded, making it similar to the case
of newly loaded object.

Noted by:	jh [1]
Reviewed by:	jh, kan
MFC after:	6 days
2010-11-04 09:29:00 +00:00
Konstantin Belousov
5dc7bbafc8 Fix style.
MFC after:	6 days
2010-11-04 09:19:14 +00:00
Konstantin Belousov
b8fc1b23be If dlopen() is called for the dso that has been already loaded as a
dependency, then the dso never has its DAG initialized. Empty DAG
makes ref_dag() call in dlopen() a nop, and the dso refcount is off
by one.

Initialize the DAG on the first dlopen() call, using a boolean flag
to prevent double initialization.

From the PR (edited):
Assume we have a library liba.so, containing a function a(), and a
library libb.so, containing function b(). liba.so needs functionality
from libb.so, so liba.so links in libb.so.

An application doesn't know about the relation between these libraries,
but needs to call a() and b(). It dlopen()s liba.so and obtains a
pointer to a(), then it dlopen()s libb.so and obtains a pointer to b().

As soon as the application doesn't need a() anymore, it dlclose()s liba.so.

Expected result: the pointer to b() is still valid and can be called
Actual result: the pointer to b() has become invalid, even though the
application did not dlclose() the handle to libb.so. On calling b(), the
application crashes with a segmentation fault.

PR:	misc/151861
Based on patch by:	jh
Reviewed by:	kan
Tested by:	Arjan van Leeuwen <freebsd-maintainer opera com>
MFC after:	1 week
2010-11-03 09:23:08 +00:00
Marcel Moolenaar
30ec71ad04 Unbreak ia64.
With r169630 I disabled symbol versioning because it broke rtld.  With
r211706 rtld got broken for ia64 & powerpc64.  It was fixed for powerpc64
with r212497.  In between, r211749 removed the exports table because the
version script handled the exports.  But wait, symbol versioning was
disabled on ia64.

With exports controlled by the version script and symbol versioning
disabled, all symbols are exported and too many symbols bind to the
definition in rtld. Let's just say that waird things happen.

So, enable symbol versioning on ia64 and apply a work-around for the
SIGSEGV that triggered r169630 to begin with: when rtld relocates
itself, it comes across r_debug_state and for some reason can't find the
definition. This causes a failure, relocation aborts and null pointers
galore. The work-around is to ignore the missing definition when rtld
is relocating itself and keep going.

Maybe with the next binutils this will all go away. Maybe not, in
which case I still need to figure out why r_debug_state cannot be found.

BTW: r_debug_state is in the symbol map -- I don't think any other rtld
symbols that rtld references are in the symbol map...
2010-10-22 04:43:04 +00:00
Ulrich Spörlein
0d9deed52c mdoc: drop redundant .Pp and .LP calls
They have no effect when coming in pairs, or before .Bl/.Bd
2010-10-08 12:40:16 +00:00
Nathan Whitehorn
9d00444d9c Fix two subtle problems in PPC32 RTLD. The first is a concurrency issue
where long PLT calls in multi-threaded environments could end up with
incorrect jmptab values. The second is that, after the addition of extended
PLT support, I forgot to update the PLT icache synchronization code to cover
the extended PLT instead of just the basic PLT.

MFC after:	10 days
2010-10-04 16:02:11 +00:00
Nathan Whitehorn
d48dde6f68 Check for undefined weak symbols during PLT binding on powerpc64, and do
not attempt to copy NULL function descriptors. This fixes LD_BIND_NOW on
powerpc64 after r211706.

Reviewed by:	kib
2010-09-12 17:04:51 +00:00
Nathan Whitehorn
789e85458b Make RTLD work on powerpc64 again. If there is a sub-directory named
MACHINE_ARCH, use that specific one, otherwise use MACHINE_CPUARCH.

Reviewed by:	imp
2010-08-24 23:19:14 +00:00
Konstantin Belousov
d4ba3a5619 Remove exports table. Export control by the version script is enough.
Reviewed by:	kan
MFC after:	3 weeks
2010-08-24 13:01:14 +00:00
Warner Losh
25faff346c MFtbemd:
Prefer MACHNE_CPUARCH to MACHINE_ARCH in most contexts where you want
to test of all the CPUs of a given family conform.
2010-08-23 22:24:11 +00:00